Bearing laminate comprising a foam layer

ABSTRACT

A bearing laminate can include a metal support layer, a foam layer overlying the metal support layer, the foam layer including a polymeric foam; and a sliding layer overlying the polymeric foam layer, the sliding layer comprising a polymer matrix. Bearing articles made from the bearing laminate can have exceptional damping properties, such as a high damping ratio combined with a low dynamic stiffness.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119(e) to U.S. PatentApplication No. 62/580,555 entitled “BEARING LAMINATE COMPRISING A FOAMLAYER,” by Julia ZIEGLER et al., filed Nov. 2, 2017, which is assignedto the current assignee hereof and incorporated herein by reference inits entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to a bearing laminate comprising a metalsupport, a foam layer including a polymeric foam, and a sliding layeroverlying the foam layer.

BACKGROUND

Maintenance-free slide bearings containing a layered structure includinga metallic support layer, an intermediate layer and a sliding layerapplied thereto are used in a wide variety of technical fields, forexample in the field of automotive, electronics, HVAC (heating ventingand air conditioning) and bicycle engineering.

There is an ongoing need to improve the known maintenance-free slidebearings by their vibration damping capability, tolerance compensationand wear resistance, and combining these properties with a low-costdesign and a cost-efficient manufacturing process.

SUMMARY

According to one embodiment, a bearing laminate comprises a metalsupport layer; a foam layer overlying the metal support layer, the foamlayer including a polymeric foam; and a sliding layer overlying thepolymeric foam layer, the sliding layer comprising a polymer matrix.

According to another embodiment, a bearing article formed from alaminate, the laminate comprises a metal support layer; a foam layeroverlying the metal support, the foam layer including a polymeric foam;and a sliding layer overlying the foam layer, the sliding layercomprising a polymer matrix.

According to a further embodiment, a method of forming a bearinglaminate comprises: providing a metal support layer, a foam layer and asliding layer; and joining the metal support layer, the foam layer, andthe sliding layer using at least one adhesive and applying pressureand/or heat treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 includes an illustration of a bearing laminate according to oneembodiment.

FIG. 2 includes an illustration of a bearing laminate according to oneembodiment.

FIG. 3 includes an illustration of a bearing laminate according to oneembodiment.

FIG. 4 includes an illustration of a bearing laminate according to oneembodiment.

FIG. 5 includes an illustration of a bearing laminate according to oneembodiment.

FIG. 6A shows an image of the testing setup for measuring the resonancefrequency of the bearing laminates according to embodiments.

FIG. 6B shows a line-drawing of a partial section of the image shown inFIG. 6A.

FIG. 6C includes a graph illustrating how to obtain the resonancefrequency.

FIG. 7A shows an image of a testing setup for simulating headrestperformance, including two stripes of bearing laminates positioned in aguide sleeve according to embodiments.

FIG. 7B shows an image of a testing setup for simulating headrestperformance, including two stripes of bearing laminates positioned in aguide sleeve and a center shaft according to embodiments.

FIG. 7C includes an illustration of a section of the testing setup forsimulating headrest performance.

FIG. 7D shows an image of a section of the testing setup for simulatingheadrest performance.

DETAILED DESCRIPTION

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of features is notnecessarily limited only to those features but may include otherfeatures not expressly listed or inherent to such process, method,article, or apparatus.

As used herein, and unless expressly stated to the contrary, “or” refersto an inclusive-or and not to an exclusive-or. For example, a conditionA or B is satisfied by any one of the following: A is true (or present)and B is false (or not present), A is false (or not present) and B istrue (or present), and both A and B are true (or present).

Also, the use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Various embodiments of the present disclosure will now be described, byway of example only, with reference to the accompanying drawings.

The present disclosure relates to a bearing laminate and a bearingarticle made from the bearing laminate having favorable vibration- andsound damping properties.

In one embodiment, as shown in FIG. 1, the bearing laminate 1 caninclude a metal support layer 2, a foam layer 3 overlying the metalsupport layer, and a sliding layer 4 overlying the foam layer. Thebearing laminate thus can contain a layer system having at least threelayers.

Further layers of the bearing laminate can include, for example, a firstadhesive layer 5 between the metal support layer 2 and the foam layer 3,and a second adhesive layer 6 between the foam layer 3 and the slidinglayer 4, as illustrated in FIG. 2.

The bearing article formed from the bearing laminate of the presentdisclosure can have exceptional vibration damping properties, such as ahigh damping ratio combined with a low dynamic stiffness.

In certain embodiments, the damping ratio of the bearing laminate can beat least 10%, such as at least 15%, or at least 17%. In otherembodiments, the damping ratio may be not greater than 50%, such as notgreater than 40%, not greater than 30%, not greater than 25%, or notgreater 20%. The damping ratio can be a value between any of the minimumand maximum values noted above, such as from 10% to 50%, from 13% to25%, or from 15% to 20%.

The dynamic stiffness of the bearing laminate can be at least 1 N/μm,such as at least 2 N/μm, at least 5 N/μm, or at least 10 N/μm. Inanother embodiment, the dynamic stiffness of the bearing laminate may benot greater than 50 N/μm, such as not greater than 30 N/μm, not greaterthan 20 N/μm, or not greater than 15 N/μm. The dynamic stiffness can bea value between any of the minimum and maximum values noted above, suchas from 1 N/μm to 50 N/μm, from 2 N/μm to 20 N/μm, or from 5 N/μm to 15N/μm.

The exceptional damping properties can be to a large extent related tothe polymeric foam present in the foam layer of the bearing laminate. Asused herein, the term polymeric foam is intended to mean a solid, highlyporous, engineered or natural material which contains gas bubblesdispersed in a solid polymeric material. The polymeric foam of thepresent disclosure can have a closed cell structure or an open cellstructure. A closed cell structure generally mean a gas-filled materialwherein the pores are not interconnected, while an open cell structurecontains connected pores which form an interconnected network. Althoughsolid foams can be divided into open-cell and closed-cell structures,the cell or pore structure of a solid foam can be a wide range ofdifferent sized cells and pores, wherein a certain amount can be ofclosed-cell structure and of open-cell structure, with one type beingthe dominating structure.

According to further embodiments, the polymeric foam contained in thefoam layer 3 can have a density according to ASTM D3574 of at least 0.15g/cm³, such as at least 0.25 g/cm³, such as at least 0.4 g/cm³, at least0.65 g/cm³, at least 0.8 g/cm³, or at least 1.0 g/cm³. In anotherembodiment, the density of the polymeric foam may be not greater than2.5 g/cm³, such as not greater than 2.0 g/cm³, not greater than 1.8g/cm³, not greater than 1.5 g/cm³, or not greater than 1.2 g/cm³. Thedensity of the polymeric foam may be a value between any of the minimumand maximum values noted above, such as from 0.15 g/cm³ to 1.5 g/cm³,from 0.25 g/cm³ to 1.2 g/cm³, or from 0.3 g/cm³ to 0.9 g/cm³.

In yet other embodiments, the polymeric foam of the polymeric foam layercan have an average pore size of at least 20 μm, such as at least 50 μm,at least 100 μm, at least 200 μm, or at least 300 μm. In another aspectthe solid foam can have an average pore size of not greater than 1500μm, such as not greater than 1000 μm, not greater than 700 μm, or notgreater than 500 μm. The solid foam can have an average pore sizebetween any of the minimum and maximum values noted above, such as from20 μm to 1500 μm, from 50 μm to 1000 μm, or from 100 μm to 400 μm.

In yet other embodiments, the polymeric foam of the foam layer can havean anisotropic behavior, wherein a statistical significant number of thepores are oriented in a specific direction, and a majority of the porescan have a non-symmetrical shape, for example an elliptical shape or atubular shape.

In a further embodiment, the polymeric foam may have a pore volume of atleast 0.4 cm³/g, such as at least 0.5 cm³/g, at least 0.7 cm³/g, or atleast 1 cm³/g. In another aspect, the pore volume of the polymeric foamcan be not greater than 100 cm³/g, such as not greater than 80 cm³/g,not greater than 50 cm³/g, not greater than 20 cm³/g, or not greaterthan 10 cm³/g. The pore volume of the polymeric foam can be a valuebetween any of the minimum and maximum values noted above, such as from0.4 cm³/g to 100 cm³/g, from 1 cm3/g to 50 cm³/g, or from 5 cm³/g to 30cm³/g.

Non-limiting examples of foam materials suitable for the polymeric foamcontained in the foam layer can be polyurethane foam, polyethylene foam,polyester foam, acrylate foam, polyvinyl chloride foam (PVC), siliconfoam, fluoropolymer foam, nitrile butadiene rubber (NBR) foam, ethylenepropylene diene monomer (EPDM) foam, polypropylene foam or anycombination thereof. In a particular embodiment, the foam material mayconsist essentially of a polyurethane foam.

The polymeric foam of the foam layer can include one or more fillers.The fillers contained in the foam layer may be in form of powders,spheres or fibers. Non-limiting examples of filler materials can beglass, carbon, CaCO₃, an antioxidant, a thermally conductive material,an electrically conductive material, or any combination thereof. In acertain embodiment, the fillers can be fibers and the fibers may beoriented within the foam layer, for example, in the length direction ofthe foam layer. Such fiber orientation can result in anisotropicproperties of the foam layer.

In aspects, the filler content of the polymeric foam layer may be atleast 0.1 wt %, such as at least 0.5 wt %, at least 1 wt %, at least 5wt %, at least 10 wt %, at least 30 wt %, at least 50 wt %, or at least70 wt % based on a total weight of the foam layer. In other aspects, thefiller amount may be not greater than 90 wt %, such as not greater than85 wt , not greater than 80 wt %, or not greater than 75 wt %. Thefiller content can be a value between any of the minimum and maximumvalues noted above, such as from 0.1 wt % to 90 wt %, from 1 wt % to 80wt %, or from 10 wt % to 50 wt % based on the total weight of the foamlayer.

In embodiments, the foam layer can have a thickness of at least 0.1 mm,such as at least 0.2 mm, at least 0.3 mm, at least 0.5 mm, or at least1.0 mm. In other embodiments, the foam layer can have a thickness of notgreater than 2.0 mm, such as not greater than 1.5 mm, not greater than1.3 mm, or not greater than 1.1 mm. The thickness of the foam layer canbe a value between any of the minimum and maximum values noted above,such as from 0.1 mm to 2.0 mm, from 0.1 mm to 1.0 mm, from 0.2 mm to 0.9mm, or from 0.4 mm to 0.8 mm.

In certain embodiments, the foam layer 3 can include a reinforcing layer7, as illustrated in FIG. 3. Non-limiting examples of a reinforcinglayer can be a mesh, a fleece, a fabric, a film or a foil. The materialof the reinforcing layer can be, for example, a metal, an alloy, apolymer, or a ceramic. In particular embodiments, the material of thereinforcing layer can have anisotropic properties. In aspects, thethickness of the reinforcing layer within the foam layer may be at least0.1 mm, such as at least 0.2 mm, or at least 0.5 mm. In other aspects,the thickness can be not greater than 1.0 mm, such as not greater than0.9 mm, or not greater than 0.7 mm. The thickness of the reinforcinglayer may be a value between any of the minimum and maximum values notedabove, such as from 0.1 mm to 1.0 mm, from 0.2 mm to 0.9 mm, or from 0.3mm to 0.8 mm.

The foam layer 3 of the bearing laminate of the present disclosure caninclude a plurality of foam sub-layers. In certain embodiments, the foamlayer 3 can include at least two foam sub-layers, such as at least threefoam sub-layers, at least four foam sub-layers, or at least five foamsub-layers. In a particular embodiment, the sub-foam layers can beconnected to each other with an adhesive

FIG. 4 illustrates an embodiment of a bearing laminate wherein the foamlayer 3 includes two foam sub-layers 3 a and 3 b, and one adhesive layer8 connecting foam sub-layer 3 a with foam sub-layer 3b. Furthermore, thebearing laminate of FIG. 4 includes a metal support 2, a sliding layer4, a first adhesive layer 5, combining metal support 2 and foamsub-layer 3 a, and a second adhesive layer 6, combining foam sub-layer 3b and sliding layer 4.

The metal support layer of the bearing laminate of the presentdisclosure can be a continuous layer including chromium, molybdenum,tungsten, manganese, iron, ruthenium, osmium, cobalt, rhodium, iridium,nickel, palladium, platinum, copper, silver, gold, gallium, indium,silicon, germanium, tin, antimony, bismuth, or any combination thereof.In particular embodiments, the metal support layer can be steel, bronze,aluminum, brass, copper, or nickel.

In certain embodiments, the metal support can comprise a coating. Thecoating of the metal support may be a paint, a sealer or a platingcontaining organic resins, e.g., epoxy resins. In certain embodiments,the coating can be a metal or alloy including chromium, molybdenum,tungsten, manganese, iron, ruthenium, osmium, cobalt, rhodium, iridium,nickel, palladium, platinum, copper, silver, gold, zinc, aluminum,gallium, indium, silicon, germanium, tin, antimony, bismuth, or anycombination thereof. Preferred coating materials of the metal supportcan be epoxy resin, nickel, copper, zinc, aluminum, or tin.

The thickness of the metal support layer can be at least 0.1 mm, such asat least 0.2 mm, at least 0.3 mm, at least 0.5 mm, or at lest 1.0 mm. Inother embodiments, the thickness of the metal support layer may be notgreater than 2.0 mm, such as not greater than 1.5 mm, or not greaterthan 1.1 mm. The thickness of the metal support layer can be a valuebetween any of the minimum and maximum values noted above, such as from0.1 mm to 2.0 mm, from 0.2 mm to 1.5 mm, or from 0.2 mm to 1.0 mm.

As illustrated in FIGS. 2, 3, and 4, the metal support layer 2, the foamlayer 3 and the sliding layer 4 of the bearing laminate of the presentdisclosure can be combined to each other by a first adhesive layer 5,attaching the metal support layer 2 to the foam layer 3, and a secondadhesive layer 6, combining the sliding layer 4 with the foam layer 3.The first adhesive layer 5 and the second adhesive layer 6 can includethe same type of adhesive or different adhesives. In the embodimentwhere the foam layer 3 includes at least two foam sub-layers, asillustrated in FIG. 4, the adhesive layer 8 combining the sub-foamlayers 3 a and 3 b can be also the same type of adhesive as used for thefirst adhesive layer 5 and/or the second adhesive layer 6 or can bedifferent. Non-limiting examples of adhesives that can be used inadhesive layers 5, 6, and/or 8 may include acrylate-based adhesive,epoxy adhesive, polyimide adhesive, fluoropolymer based adhesive, alow-temperature hot melt adhesive, in particular ethylene-vinyl acetateor polyether-polyamide copolymers, or any combination thereof. In aparticular embodiment, the adhesive can be in both the first adhesivelayer 5 and the second adhesive layer 6 an acrylate-based pressuresensitive adhesive.

The thickness of the first adhesive layer 5, the second adhesive layer6, and of any adhesive layer combining two foam sub-layers can be thesame or different from each other. In certain aspects, the thickness ofthe adhesive layers can be at least 0.001 mm, such as at least 0.005 mm,at least 0.01 mm, or at least 0.05 mm. In other aspects, the thicknessof the adhesive layers may be not greater than 0.5 mm, such as notgreater than 0.4 mm, not greater than 0.3 mm, not greater than 0.2 mm,or not greater than 0.1 mm. The thickness of the adhesive layers can bea value between any of the minimum and maximum values noted above, suchas from 0.001 mm to 0.5 mm, from 0.05 mm to 0.4 mm, or from 0.01 mm to0.25 mm.

The sliding layer 4 overlying the foam layer 3 can include a polymermatrix. Non-limiting material examples of the polymer matrix can bepolytetrafluoroethylene (PTFE), modified polytetrafluoroethylene(mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene(PFA), tetrafluoroethylene-hexafluoropropylene (FEP),tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA),polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene(ECTFE), polyimide (PI), polyamidimide (PAI), polyphenylene sulfide(PPS), polyethersulofone (PES), polyphenylene sulfone (PPSO2), liquidcrystal polymers (LCP), polyetherketone (PEK), polyether ether ketones(PEEK), aromatic polyesters (Ekonol), of polyether-ether-ketone (PEEK),polyetherketone (PEK), liquid crystal polymer (LCP), polyamide (PA),polyoxymethylene (POM), polyethylene (PE)/UHMPE, polypropylene (PP),polystyrene, styrene butadiene copolymers, polyesters, polycarbonate,polyacrylonitriles, polyamides, styrenic block copolymers, ethylenevinyl alcohol copolymers, ethylene vinyl acetate copolymers, polyestersgrafted with maleic anhydride, poly-vinylidene chloride, aliphaticpolyketone, liquid crystalline polymers, ethylene methyl. acrylatecopolymer, ethylene-norbomene copolymers, polymethylpentene and ethyleneacrylic acid copolymer, or any combination thereof. In a particularembodiment, the polymer matrix can include PTFE.

In certain embodiments, the sliding layer 4 can include a reinforcinglayer 9, as illustrated in bearing laminate of FIG. 5, including asupport layer 2, a first adhesive layer 5, a foam layer 3, a secondadhesive layer 6, a sliding layer 4, and a reinforcing layer 9 withinthe sliding layer 4. Non-limiting examples of a reinforcing layer 9 canbe a film, a foil or a porous layer like a mesh, a fleece, a fabric orstretched material. The material of the reinforcing layer can be, forexample, a metal, an alloy, a polymer, or a ceramic. In particularembodiments, the material of the reinforcing layer can have anisotropicproperties. In aspects, the thickness of the reinforcing layer withinthe sliding layer may be at least 0.1 mm, such as at least 0.2 mm, or atleast 0.5 mm. In other aspects, the thickness can be not greater than1.0 mm, such as not greater than 0.9 mm, or not greater than 0.7 mm. Thethickness of the reinforcing layer 9 may be a value between any of theminimum and maximum values noted above, such as from 0.1 mm to 1.0 mm,from 0.2 mm to 0.9 mm, or from 0.3 mm to 0.8 mm.

In embodiments, the sliding layer can have a thickness of at least 2 μm,such as at least 10 μm, at least 20 μm, at least 30 μm, at least 50 μm,at least 100 μm, at least 200 μm, or at least 500 μm. In otherembodiments, the sliding layer can have a thickness of not greater than1000 μm, such as not greater than 900 μm, not greater than 800 μm, notgreater than 600 μm, or not greater than 550 μm. The thickness of thesliding layer can be a value between any of the minimum and maximumvalues noted above, such as from 2 μm to 1000 μm, from 10 μm to 800 μm,or from 100 μm to 600 μm.

In certain embodiments of the laminate of the present disclosure, athickness ratio of the sliding layer 4 to the foam layer 3 can be atleast 1:10, such as at leas 1:5 or at least 1:1. In other certainembodiments, the thickness ratio of the sliding layer to the foam layermay be not greater than 10:1, such as not greater than 5:1, or notgreater than 2:1.

In yet further embodiments, the thickness ratio of the foam layer 3 tothe total thickness of the bearing laminate can be at least 1:3, such asat least 1:2.5, at least 1:2, or at least 1:1.8. In other embodiments,the thickness ratio of the foam layer 3 to the total thickness of thelaminate may be not greater than 1:1.2, such as not greater than 1:1.3or not greater than 1:1.4. The thickness ratio of the foam layer to thetotal thickness of the laminate can be a value between any of theminimum and maximum values noted above, such as from 1:3 to 1:1.12 orfrom 1:2 to 1:1.14.

The bearing laminate of the present disclosure can be formed byproviding sheet-like materials of each of the metal support layer 2, thefoam layer 3 and the sliding layer 4, and joining the sheets underapplied pressure and/or heat.

In one embodiment, the foam layer can be a sheet coated on both sideswith an adhesive and joined under pressure with the metal support layerand the sliding layer. In a particular aspect, the adhesive may be apressure sensitive adhesive including an acrylate compound.

The bearing laminate of the present disclosure can be used for forming abearing article which may be adapted for use in a head restraint, a balljoint, a hinge, a seat structure, as a friction plate, as a stabilizerbearing, a tolerance compensation component, or as a noise dampener.

Many different aspects and embodiments are possible. Some of thoseaspects and embodiments are described herein. After reading thisspecification, skilled artisans will appreciate that those aspects andembodiments are only illustrative and do not limit the scope of thepresent invention. Embodiments may be in accordance with any one or moreof the embodiments as listed below.

Embodiments

Embodiment 1. A bearing laminate comprising:

-   a metal support layer;-   a foam layer overlying the metal support layer, the foam layer    including a polymeric foam; and-   a sliding layer overlying the polymeric foam layer, the sliding    layer comprising a polymer matrix.

Embodiment 2. A bearing article formed from a bearing laminate, thebearing laminate comprising:

-   a metal support layer;-   a foam layer overlying the metal support layer, the foam layer    including a polymeric foam; and-   a sliding layer overlying the polymeric foam layer, the sliding    layer comprising a polymer matrix.

Embodiment 3. A method for forming a bearing laminate, comprising:providing a metal support layer, a foam layer including a polymericfoam, and a sliding layer; and

-   joining the metal support layer, the foam layer, and the sliding    layer using at least one adhesive and applying pressure and/or heat    treatment.

Embodiment 4. The bearing laminate or method of embodiments 1, 2, or 3,wherein the laminate has a dynamic stiffness of at least 1 N/μm, such asat least 2 N/μm, at least 5 N/μm, at least 7 N/μm, or at least 10 N/μm.

Embodiment 5. The bearing laminate or method of embodiments 1, 2, or 3,wherein the laminate has a dynamic stiffness of not greater than 50N/μm, such as not greater than 30 N/μm, not greater than 25 N/μm, notgreater than 20 N/μm, or not greater than 15 N/μm, or not greater than10 N/μm.

Embodiment 6. The bearing laminate of embodiments 4 or 5, wherein thelaminate has a dynamic stiffness of at least 5 N/μm and not greater than20 N/μm.

Embodiment 7. The bearing laminate or method of any of the precedingembodiments, wherein the laminate has a damping ratio of at least 10%,such as at least 15%, or at least 17%, or at least 19%.

Embodiment 8. The bearing laminate or method of any of the precedingembodiments, wherein the laminate has a damping ratio not greater than50%, not greater than, 40%, not greater than 30%, not greater than 25%,not greater than 23%, or not greater than 20%

Embodiment 9. The bearing laminate of embodiments any of the precedingembodiments, wherein the laminate has a damping ratio of at least 17%and not greater than 30%.

Embodiment 10. The bearing laminate or method of any of the precedingembodiments, further comprising a first adhesive layer between the metalsupport and the foam layer and a second adhesive layer between the foamlayer and the sliding layer.

Embodiment 11. The bearing laminate or method according to embodiment10, wherein the first adhesive layer and the second adhesive layercomprise a same type of adhesive.

Embodiment 12. The bearing laminate or method of embodiment 10, whereinthe first adhesive layer includes a different adhesive than the secondadhesive layer.

Embodiment 13. The bearing laminate or method of embodiments 10, 11, or12, wherein the first adhesive layer and/or the second adhesive layerinclude a pressure sensitive adhesive.

Embodiment 14. The bearing laminate or method of any of the precedingembodiments, wherein the polymeric foam includes a polyurethane foam, apolyethylene foam, a polyester foam, an acrylate foam, a polyvinylchloride (PVC) foam, a silicon foam, a fluoropolymer foam, a nitrilebutadiene rubber (NBR) foam, a ethylene propylene diene monomer (EPDM)foam, a polypropylene foam or any combination thereof.

Embodiment 15. The bearing laminate or method of embodiment 14, whereinthe polymeric foam includes polyurethane foam.

Embodiment 16. The bearing laminate or method of embodiment 15, whereinthe polymeric foam consists essentially of polyurethane foam.

Embodiment 17. The bearing laminate or method of any of the precedingembodiments, wherein the polymeric foam has a closed cell structure.

Embodiment 18. The bearing laminate or method of any of embodiments 1 to16, wherein the polymeric foam has an open cell structure.

Embodiment 19. The bearing laminate or method of any of the precedingembodiments, wherein the foam layer includes at least two foamsub-layers.

Embodiment 20. The bearing laminate of method of embodiment 19, whereinthe at least two foam sub-layers are connected to each other by anadhesive.

Embodiment 21. The bearing laminate or method of any of the precedingembodiments, wherein the foam layer further comprises a reinforcinglayer.

Embodiment 22. The bearing laminate or method of embodiment 21, whereinthe reinforcing layer includes a mesh, a stretched material, a fleece, afabric, a film, or a foil.

Embodiment 23. The bearing laminate or method of embodiments 21 or 22,wherein a material of the reinforcing layer includes a metal, a ceramic,glass fibres, carbon fibres, a plastic or any combination thereof.

Embodiment 24. The bearing laminate or method of any of embodiments 21,22, or 23, wherein the reinforcing layer has anisotropic properties.

Embodiment 25. The bearing laminate or method of any of the precedingembodiments, wherein the foam layer has a thickness of at least 0.1 mm,such as at least 0.2 mm, at least 0.3 mm, at least 0.5 mm, or at least1.0 mm.

Embodiment 26. The bearing laminate or method of any of the precedingembodiments, wherein the foam layer has a thickness of not greater than2.0 mm, such as not greater than 1.5 mm, not greater than 1.3 mm, or notgreater than 1.1 mm.

Embodiment 27. The bearing laminate or method of any of the precedingembodiments, wherein a thickness ratio of the sliding layer to thepolymeric foam layer is at least 1:10, such as at leas 1:5 or at least1:1.

Embodiment 28. The bearing laminate or method of any of the precedingembodiments, wherein a thickness ratio of the sliding layer to thepolymeric foam layer is and not greater than 10:1, such as not greaterthan 5:1, or not greater than 2:1.

Embodiment 29. The bearing laminate or method of any of the precedingembodiments, wherein a thickness ratio of the polymeric foam layer to atotal thickness of the laminate is not greater than 1:1.2, such as notgreater than 1:1.3, or not greater than 1:1.4, or not greater than1:1.6.

Embodiment 30. The bearing laminate or method of any of the precedingembodiments, wherein a thickness ratio of the polymeric foam layer to atotal thickness of the laminate is at least 1:3, or at least 1:2.5, orat least 1:2, or at least 1:1.8.

Embodiment 31. The bearing laminate or method of any of the precedingembodiments, wherein the foam layer further includes a filler.

Embodiment 32. The bearing laminate or method of embodiment 31, whereinthe filler of the foam layer includes a glass, CaCO₃, an antioxidant, athermally conductive material, an electrically conductive material, orany combination thereof.

Embodiment 33. The bearing laminate or method of embodiments 31 or 32,wherein an amount of the filler in the foam layer is at least 0.1 wt %based on the total weight of the foam layer, such as at least 5.0 wt %,at least 10 wt %, or at least 70 wt %.

Embodiment 34. The bearing laminate or method of embodiments 31, 32 or33, wherein an amount of the filler in the foam layer is not greaterthan 90 wt %, such as not greater than 85 wt %, not greater than 80 wt%, or not greater than 75 wt %.

Embodiment 35. The bearing laminate or method of any of the precedingembodiments, wherein a material of the metal support layer includeschromium, molybdenum, tungsten, manganese, iron, ruthenium, osmium,cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver,gold, zinc, aluminum, gallium, indium, silicon, germanium, tin,antimony, bismuth, alloys, or any combination thereof.

Embodiment 36. The bearing laminate or method of any of the precedingembodiments, wherein the metal support layer includes steel, bronze,aluminum, brass, copper, nickel, or any combination thereof.

Embodiment 37. The bearing laminate or method according to any one ofthe preceding embodiments, wherein the metal support further comprises acoating, wherein the coating includes an organic resin, a metal or analloy.

Embodiment 38. The bearing laminate or method according to embodiment37, wherein the metal or alloy of the coating includes chromium,molybdenum, tungsten, manganese, iron, ruthenium, osmium, cobalt,rhodium, iridium, nickel, palladium, platinum, copper, silver, gold,zinc, aluminum, gallium, indium, silicon, germanium, tin, antimony,bismuth, or any combination thereof.

Embodiment 39. The bearing laminate or method according to embodiments37 or 38, wherein the coating of the metal support includes an epoxyresin, nickel, copper, zinc, aluminum, tin, or any combination thereof.

Embodiment 40. The bearing laminate or method of any of the precedingembodiments, wherein the metal support has a thickness of at least 0.1mm, such as at least 0.2 mm, at least 0.3 mm, at least 0.5 mm, or atleast 0.8 mm.

Embodiment 41. The bearing laminate or method of any of the precedingembodiments, wherein the metal support has a thickness of and notgreater than 2.0 mm, such as not greater than 1.5 mm, or not greaterthan 1.0 mm.

Embodiment 42. The bearing laminate or method of any of the precedingembodiments, wherein the polymer matrix of the sliding layer includespolytetrafluoroethylene (PTFE), modified polytetrafluoroethylene(mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene(PFA), tetrafluoroethylene-hexafluoropropylene (FEP),tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA),polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene(ECTFE), polyimide (PI), polyamidimide (PAI), polyphenylene sulfide(PPS), polyethersulofone (PES), polyphenylene sulfone (PPSO2), liquidcrystal polymer (LCP), polyetherketone (PEK), polyether ether ketone(PEEK), aromatic polyester of polyether-ether-ketone (EKONOL),polyetherketone (PEK), liquid crystal polymer (LCP), polyamide (PA),polyoxymethylene (POM), polyethylene (PE)/UHMPE, polypropylene (PP),polystyrene, styrene butadiene copolymer, polyester, polycarbonate,polyacrylonitriles, polyamide, styrenic block copolymer, ethylene vinylalcohol copolymer, ethylene vinyl acetate copolymer, polyester graftedwith maleic anhydride, poly-vinylidene chloride, aliphatic polyketone,ethylene-methylacrylate copolymer, ethylene-norbomene copolymer,copolymer of polymethylpentene and ethylene acyrilic acid, or anycombination thereof.

Embodiment 43. The bearing laminate or method of embodiment 42, whereinthe polymer matrix includes PTFE.

Embodiment 44. The bearing laminate or method of any of the precedingembodiments, wherein the sliding layer further comprises a filler.

Embodiment 45. The bearing laminate or method of embodiment 44, whereinthe filler of the sliding layer includes carbon, glass, graphite,EKONOL®, aluminium oxide, molybdenum sulfide, bronze, silicon carbide,polytetra fluoroethylene (PTFE), polyimide (PI), polyamidimide (PAI),polyphenylene sulfide (PPS), polyphenylene sulfone (PPSO2), liquidcrystal polymers (LCP), polyether ether ketones (PEEK), polyethersulfone(PES), polyetherketone (PEK), aromatic polyesters, glass fibers, carbonfibers, PTFE fibers, PPS fibers, aramids, wollastonite or bariumsulfate.

Embodiment 46. The bearing laminate or method of embodiment 45, whereinthe filler includes graphite, carbon, Ekonol, or any combinationthereof.

Embodiment 47. The bearing laminate or method of embodiments 44, 45, or46, wherein the polymer matrix includes PTFE and the filler includesgraphite, carbon, Econol or any combination thereof.

Embodiment 48. The bearing laminate or method of any of the precedingembodiments, wherein the sliding layer further comprises a reinforcinglayer.

Embodiment 49. The bearing laminate or method of embodiment 48, whereinthe reinforcing layer includes a film, a foil, a mesh, a fleece a fabricor a stretched material.

Embodiment 50. The bearing laminate or method of embodiments 48 or 49,wherein a material of the reinforcing layer includes a metal, a ceramic,glass fibers, carbon fibers, a plastic or any combination thereof.

Embodiment 51. The bearing laminate or method of any of embodiments 48,49, or 50, wherein the reinforcing layer has anisotropic properties.

Embodiment 52. The bearing laminate or method of any of the precedingembodiments, wherein the sliding layer has a thickness of at least 2 μm,such as at least 10 μm, at least 15 μm, at least 20 μm, at least 30 μm,at least 50 μm, at least 100 μm, or at least 200 μm.

Embodiment 53. The bearing laminate or method of any of the precedingembodiments, wherein the sliding layer has a thickness of not greaterthan 1000 μm, such as not greater than 900 μm, not greater than 800 μm,not greater than 600 μm, or not greater than 400 μm.

Embodiment 54. The bearing laminate or method of any of the precedingembodiments, wherein the polymeric foam has a density of at least 0.15g/cm³, such as at least 0.25 g/cm³, such as at least 0.4 g/cm³, at least0.65 g/cm³, at least 0.8 g/cm³, or at least 1.0 g/cm³.

Embodiment 55. The bearing laminate or method of any of the precedingembodiments, wherein a density of the polymeric foam may be not greaterthan 2.5 g/cm³, such as not greater than 2.0 g/cm³, not greater than 1.8g/cm³, not greater than 1.5 g/cm³, not greater than 1.2 g/cm³ or notgreater than 1.0 g/cm³, or not greater than 0.9 g/cm³.

Embodiment 56. The bearing laminate or method of embodiments 54 or 55,wherein the polymeric foam has a density of at least 0.15 g/cm³ to notgreater than 1.5 g/cm³, of at least 0.25 g/cm³ to not greater than 1.2g/cm³, or from at least 0.3 g/cm³ to not greater than 0.9 g/cm³.

Embodiment 57. The bearing laminate or method of embodiment 56, whereinthe polymeric foam has a density of at least 0.3 g/cm³ to not greaterthan 0.9 g/cm³

Embodiment 58. The bearing article of any of embodiments 2 or 4-57,wherein the bearing article is adapted for use in a head restraint, aball joint, a hinge, a seat structure, as a friction plate, as astabilizer bearing, or as a dampener.

EXAMPLES

The following non-limiting examples illustrate the present invention.

Example 1

Preparing of bearing laminates.

Bearing laminates were produced by using the following four polyurethanefoams: 1) SecureEdge® OP-5C, 2) NORBOND® OP7, and 3) NORBOND® Z520H and4) Normount V2800. All four foams are products from Saint-GobainPerformance Plastics. The densities and thicknesses of the four foammaterials are listed in Table 1 below. All polyurethane foams containedon both surfaces a modified acrylic pressure sensitive adhesive. At oneside of each polyurethane foam was applied a 0.25 mm steel backing(material 1.0338). On the other side of each polyurethane foam wasapplied a) an 0.25 mm thick etched PTFE compound tape as sliding layer,comprising 20-25% EKONOL®, an aromatic polyester, as filler (see samples1-3 of Table 1), or b) an 0.25 mmm thick etched PTFE tape (see sample 4)or c) a PTFE tape including 25% graphite and carbon as fillers (seesample 5 in Table 1). The polyurethane foam, metal backing and slidinglayer for each bearing laminate were joined with a batch press under apressure of 38 MPa, at a temperature of 40° C., and for a time of 150seconds.

The obtained bearing laminates are called hereafter: 1)Me-FoamOP5C-PTFE/EKO; 2) Me-FoamOP7-PTFE/EKO; 3) Me-FoamZ520H-PTFE/EKO,4) Me-FoamV2800-PTFE, and 5) Me-FoamV2800-PTFE/CG.

Example 2

Testing of dynamic stiffness and damping ratio.

Table 1 below summarizes the measured average dynamic stiffness andaverage damping ratio for bearing laminates “Me-FoamV2800-PTFE” and“Me-FoamV2800-PTFE/CG produced in Example 1.

Table 1 further includes the tested average dynamic stiffness andaverage damping ratio for two comparative bearing laminates (X2T100CGand X2T100E), which do not include a polymeric foam layer asintermediate layer, and have a Norglide X2 structure: 250 μm PTFEcompound, 250 μm metal backing, and 500 μm Rubber coating.

TABLE 1 Density Thickness Average Average of of Foam Dynamic DynamicLaminate Foam layer Stiffness Damping Sample Structure [g/cm3] [mm][N/μm] Ratio [%] 1 Me-FoamOP5C- 0.72 0.8 PTFE/EKO 2 Me-FoamOP7- 0.53 0.8PTFE/EKO 3 Me-FoamZ520H- 0.48 0.5 PTFE/EKO 4 Me-FoamV2800- 0.48 0.8 8 23PTFE 5 Me-FoamV2800- 0.48 0.8 6.1 19.5 PTFE/CG 6 X2T100CG n.r n.r 40 8.07 X2T100E n.r n.r. 28 15.5

The results summarized in Table 1 show that the highest damping ratiocould be obtained with the laminates including a polyurethane foam layerbetween metal support and sliding layer. The corresponding low dynamicstiffness is typical, because dynamic stiffness and damping ratiogenerally have an inverse trend. Comparative samples 6 and 7, i.e.,X2T100CG and X2T100E, which do not include a foam layer and have thetypical Norglide X2 structure, showed the lowest dynamic damping ratiosof the tested samples and the highest stiffness values.

Testing of Damping Ratio

The damping ratio is a measure of what fraction of vibration energy isdissipated as heat for every oscillation causing the vibration of ashaft (61) in the center of the tested bearing (62). (see FIGS. 6A and6B). To measure damping ratio, broadband excitation (0-20 kHz) wasinjected into the system by a vibration shaker (67) and the force inputinto the housing (63) was measured using a force transducer (64). Thevibration was propagated through the housing (63) and into the bearing(62), through the bearing and into the shaft (61). A fishing wire (65)was used as suspension to isolate external influence. The outputvibration from the shaft was then measured as an acceleration using anaccelerometer (66).

A natural logarithm was taken of the ratio between the outputacceleration and the input force to gain a frequency response functionof the system in decibels. A stiff housing and shaft were used to obtainthe first resonance peak in the graph, of frequency f_(n), as the firstorder mode of the bearing. Either side of the peak at a value of 3 dBless than the peak value, the frequencies f₁ and f₂ were taken as thehalf power values below and above the peak, respectively. The dampingratio was then calculated by taking a ratio of the difference between f₁and f₂ and the resonance frequency f_(n) according to the followingequation:

Damping Ratio=(half power bandwidth/2×resonance frequency)×100%

For the test, Brüel and Kjær equipment was used, including: 8201 forcetransducer with a 4675 charge converter; 4219-002 accelerometer; LAN XIdata acquisition unit; and Pulse LabShop software. The housing and shaftwere made from hardened tool steel and designed to have between 2-3%compressions of the bearing.

An illustration of the testing setup is shown in FIGS. 6A and 6B. Thegraph obtained during the testing to derive the resonance frequency canbe seen in FIG. 6C.

Testing of Dynamic Stiffness

For the testing of the dynamic stiffness, the resonance frequency wasobtained as the value f_(n) described in the testing method for thedamping ratio. The effective mass (m_(e)) was calculated using the massof the housing (m₁) and the mass of the shaft (m₂) and the followingequation:

$m_{e} = \frac{m_{1}m_{2}}{m_{1} + m_{2}}$

The dynamic stiffness, k_(d), is then calculated using the followingequation:

k_(d)=m_(e)4π²f_(n) ²

As an example the dynamic stiffness value of the Me-FoamV2800PTFE/CGsample of k_(d)=6.069 N/pm was obtained using the following values:

Resonance frequency=f_(n)=2.263 kHz

Housing mass=m₁=1.0539 kg

Shaft mass=m₂=0.0309 kg

$k_{d} = {\frac{m_{1}m_{2}}{m_{1} + m_{2}}4\pi^{2}f_{n}^{2}}$$k_{d} = {\frac{1.0539*0.0309}{1.0539 + 0.0309}4\pi^{2}2.263^{2}}$k_(d) = 6.069  N/µm

Example 3

Simulation of performance in headrest.

The bearing laminates Me-FoamOP5C-PTFE/EKO, Me-FoamOP7-PTFE/EKO, andMe-FoamZ520H described in Example 1 and Table 1 were tested in asimulated headrest assembly with regard to the required moving force tomove the shaft, while the housing and the tested bearing are fixed.

For the testing, two 50 mm wide stripes of each bearing laminate wereformed into two rings and mounted into a guide sleeve. Thereafter, ashaft with 1 mm interference fit was assembled in the center of theguide sleeve, as illustrated in FIG. 7A and 7B.

The movement of a headrest was simulated under room temperature, at 90°C., and at −40° C. and during a certain amount of moving cycles (seeTable 2). The testing set-up for the headrest simulation is furtherillustrated in FIGS. 7C and 7D. The testing was conducted under thefollowing conditions: stroke: +/−50 mm, speed 3 mm/s, and press fit:0.5-1 mm.

Table 2 illustrates a summary of the test results. The results show thatall tested laminates require a low average moving force of below 10 N.In all tested laminates, the moving force increased by a minor amount ifthe temperature was increased to 90° C. or decreased to −40° C. Thelowest moving force was measured for the laminate including foam Z520.Reason could be a lower thickness of the foam layer (0.5 mm instead of0.8 mm), or the lower density of the foam. Although foams OPSC and OP7had different densities, this did not show differences in the testedmoving force.

TABLE 2 Me- Me- Me- Amount FoamOP5C- FormOP7- FoamZ520H- of CyclesPTFE/EKO PTFE/EKO PTFE/EKO Avg. Moving 1000 6.5 6.5 2.2 Force RT [N]Avg. Moving 10 7.1 7.1 2.4 Force 90° C. [N] Avg. Moving 10 8.3 8.2 3.1Force −40° C. [N]

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope of theinvention.

What is claimed is:
 1. A bearing laminate comprising: a metal supportlayer; a foam layer overlying the metal support layer, the foam layerincluding a polymeric foam; and a sliding layer overlying the polymericfoam layer, the sliding layer comprising a polymer matrix.
 2. Thebearing laminate of claim 1, wherein the laminate has a dynamicstiffness of at least 1 N/μm and not greater than 20 N/μm.
 3. Thebearing laminate of claim 1, wherein the laminate has a damping ratio ofat least 17% and not greater than 50%.
 4. The bearing laminate of claim1, further comprising a first adhesive layer between the metal supportand the foam layer and a second adhesive layer between the foam layerand the sliding layer.
 5. The bearing laminate of claim 1, wherein thepolymeric foam includes a polyurethane foam, a polyethylene foam, apolyester foam, an acrylate foam, a polyvinyl chloride (PVC) foam, asilicon foam, a fluoropolymer foam, a nitrile butadiene rubber (NBR)foam, a ethylene propylene diene monomer (EPDM) foam, a polypropylenefoam or any combination thereof.
 6. The bearing laminate of claim 5,wherein the polymeric foam includes polyurethane foam.
 7. The bearinglaminate of claim 1, wherein the foam layer includes at least two foamsub-layers.
 8. The bearing laminate of claim 7, wherein the at least twofoam sub-layers are connected to each other by an adhesive.
 9. Thebearing laminate of claim 1, wherein the foam layer further comprises areinforcing layer.
 10. The bearing laminate of claim 1, wherein the foamlayer has a thickness of at least 0.1 mm and not greater than 2.0 mm.11. The bearing laminate of claim 1, wherein the polymeric foam has adensity of at least 0.2 g/cm³ and not greater than 0.9 g/cm³.
 12. Abearing article formed from a bearing laminate, the bearing laminatecomprising: a metal support layer; a foam layer overlying the metalsupport layer, the foam layer including a polymeric foam; and a slidinglayer overlying the polymeric foam layer, the sliding layer comprising apolymer matrix.
 13. The bearing article of claim 12, wherein the bearingarticle is adapted for use in a head restraint, a ball joint, a hinge, aseat structure, as a friction plate, a stabilizer bearing, or adampener.
 14. The bearing article of claim 12, wherein the bearinglaminate has a dynamic stiffness of at least 1 N/μm and not greater than20 N/μm.
 15. The bearing article of claim 12, wherein the bearinglaminate has a damping ratio of at least 17% and not greater than 50%.16. The bearing article of claim 12, wherein the polymeric foam includesa polyurethane foam, a polyethylene foam, a polyester foam, an acrylatefoam, a polyvinyl chloride (PVC) foam, a silicon foam, a fluoropolymerfoam, a nitrile butadiene rubber (NBR) foam, a ethylene propylene dienemonomer (EPDM) foam, a polypropylene foam or any combination thereof.17. The bearing article of claim 16, wherein the polymeric foam includespolyurethane foam.
 18. A method for forming a bearing laminate,comprising: providing a metal support layer, a foam layer including apolymeric foam, and a sliding layer; and joining the metal supportlayer, the foam layer, and the sliding layer using at least one adhesiveand applying pressure and/or heat treatment.
 19. The method of claim 18,wherein the foam layer includes a polyurethane foam.
 20. The method ofclaim 18, wherein a thickness ratio of the polymeric foam layer to atotal thickness of the laminate is at least 1:3 and not greater than1:1.2.